New featuresContent server: Allow conversion of booksClick the convert icon in the top bar of the book details page to convert a book. Note that conversion only works for logged in users who have permission to make changes to the calibre library.

Kindle Fire driver: Send books by default to the "kindle" folder instead of the "Books" folder to workaround a change in the Fire firmware that causes the Kindle to not recognize files in the Books folder.Linux installer: Also fix the execute bits in the umask if the user runs the installer with a umask that prevents files from being world executable.Sort the entries in the show column menu alphabetically.Closes tickets: 1778155

New featuresAdd a option to draw a grid in the main book list (Preferences->Look & feel)Edit book: Allow removing the currently highlighted tag (while keeping its contents) by pressing Ctrl+>. You can also add a tool to do it via Preferences->ToolbarsContent server: When defining a color scheme for the in browser viewer allow specifying the link color as well as the foreground and background.Closes tickets: 1735904

Edit book: Show a popup after a fix all html/beautify all files so the user can easily see what was changed, if needed.Closes tickets: 1785482

Bug fixesContent server: Display custom comments field on the book details page in the same order as in the calibre GUIEdit book: Fix open image editors not being updated when image file is replacedFix keyboard shortcuts for Edit book tools created from plugins not workingPDF Output: Fix error when trying to convert books that do not specify a language in their metadata.Closes tickets: 1783563